Questions we ask reveal where our interests lie. What we don’t ask about, we probably don’t think about. And if the subject is something we don’t think about, we likely don’t regard it as important.

This statement of the self-evident is partly, I think, what underlies the objection of so many Americans at being asked, by the U.S. Census Bureau, to declare their race.

It’s not just repugnant for the millions who believe that American-ness trumps any of the other categories into which we might fit. It does not only offend those who genuinely believe with Dr. Martin Luther King Jr. that Americans ought to be judged not by the color of our skin but by the content of our character.

When it comes to the census, only some strands of the American story apparently are worth pulling out for a closer look.

This year, the census has just 10 questions, ending with: Where do you come from and what is your race?

If you are “white,” that’s it. You might be from Zimbabwe or Iran or Ireland, but that’s of no interest. Your white skin makes it so, so please skip Question 8 because the bureau does not care where you or your forebears come from.

If you are “black, African Am., or Negro,” you’re done too. You might come from Haiti or Malawi, or have ancestors from Ghana, but it’s not germane.

But if you are a Pacific Islander? Please, go into detail! Are you native Hawaiian? Guamanian or Chamorro? Samoan? Or “other,” such as Fijian or Tongan?

And goodness, but the census is fascinated with persons of “Hispanic, Latino, or Spanish Origin.” Hispanics have a question all to themselves: Are you Mexican, Mexican-American, Chicano, Puerto Rican, Cuban? Or a write-in: Are you Argentinean, Colombian, Dominican, Nicaraguan, Salvadoran or a Spaniard?

This obsession with the geographic origins of some Americans and the utter indifference to the geographic origins of other Americans flies in the face of the constant assurance of census officials that by filling out our forms we are doing a wonderful service for genealogists. Really?

This racial slicing and dicing is not just awful, it’s hurtful, and it undermines the American project.

When President Barack Obama gave his big breakout speech at the 2004 Democratic Convention, he got a huge response when he said, “There is not a black America and a white America and a Latino America and an Asian America. There’s the United States of America!”

Sadly, according to the census, those are the only kinds of America.

Examiner Columnist Meghan Cox Gurdon is a former foreign correspondent and a regular contributor to the books pages of The Wall Street Journal.